by Devin Sugameli
As social networking sites like Facebook and Twitter continue to explode, the question for companies is no longer whether or not to invest in their social media presence, but how to quantitatively measure their success on these platforms. To date there is no one foolproof formula for calculating the value of a Facebook fan or Twitter follower, but there are plenty of ways to track the success of individual campaigns in terms of sales, customer response, and ensuing buzz. Here are our top 4 easiest ways to measure campaign ROI:

1) Discount codes and special offers - Probably the easiest and most popular way to directly measure the ROI of any promotional medium is to use it to offer specific discount codes, coupons, or special offers. More than any other suggestion on this list, tracking the number of coupon redemptions is a sure-fired way to tie the relative success of your social media presence back to hard sales. There is one downside: namely, that the nature of social media is to share information, and a Facebook fan can just as easily repost your special discount code to give non-fans equal access, making it more difficult to track.

2) Trackable links - If you aren't in a position to offer special discounts to track sales, employing trackable links in your social media posts is the next best way to measure your influence. Compare the time spent surfing on your company's website by a Twitter follower to that by an e-mail newsletter recipient or Facebook fan to discover who is more receptive to your message.

3) Facebook ads to your fans - If you're considering using Facebook's advertising platform to drive more traffic to your site, consider running two separate campaigns: ads to users not yet connected to your page and ads to those who are. If the ads targeted specifically to your fans are achieving significantly higher click-through rates than those of the non-fan campaign, at the least you know that a fan is generally more likely to respond to calls to action from your brand than a user who has yet to connect with your page.

4) Monitoring user feedback and organic conversation - Whether it's your Facebook Post Quality rating, the number of @ replies you receive on twitter, or the number of comments on your latest YouTube video, user feedback is an important way to measure your social media success. More often than not, these replies and comments are posted publicly, spreading the word about your brand, product, or organization to the user's own social network. Monitoring the conversation around you may not enable you to directly track sales, but it will help you to track ROI in terms of word of mouth and free publicity.

Do you have any suggestions for easy ways to measure ROI? Tell us in the comments!